No matter what the definition, libre content can be shared and adapted by any person for any purpose, including commercial purposes. The only requirements are minor, and include attribution (you need to give credit to those whose work you're using) and copyleft (if you use the content in your own work, your work has to be under the same licence as the content you use).

Uncharted Worlds ● 'Uncharted Worlds is a Space Opera roleplaying game built upon the Apocalypse World rules. It’s inspired by the big, bold, larger-than-life space-faring epics like Mass Effect, Firefly, Star Trek, and by games like Traveller, Masters of Orion, Starcraft (and a bit of Galaxy Trucker).'

Why Open Education Matters ● A contest where people were asked to 'Create a short video that explains the benefits and promise of Open Educational Resources for teachers, students and schools everywhere.'

Wikipedia:Sound/list ● "This is an incomplete list of full length free content musical works available on Wikipedia or Wikimedia Commons, with special emphasis on works that are (or should be) linked in Wikipedia articles." (Mainly classical music)

WikiPremed MCAT Course ● 'WikiPremed's mission is to lower economic barriers to becoming a doctor and to improve the quality of MCAT review for everyone.'

Wikinews ● "The Wikinews project is a free content news source of the Wikimedia Foundation that seeks to provide content, free of charge, where everyone is invited to contribute reports about events large and small, either from direct experience, or summarized from elsewhere."

CERN Open Hardware License ● 'In the spirit of knowledge sharing and dissemination, the CERN Open Hardware Licence (CERN OHL) governs the use, copying, modification and distribution of hardware design documentation, and the manufacture and distribution of products.'